1. Technical Field
The present invention relates to power saving control for a network system including a plurality of devices connected to one another via a network.
2. Related Art
Control associated with power saving of a device has been known from a viewpoint of reducing power consumption. If the device is not used for a specific period of time under a normal operation condition (hereinafter referred to as “a normal mode”), the operation condition of the device is moved to a condition in which an amount of power consumption is smaller than that in the normal mode (hereinafter referred to as “a power saving mode”). Further, if a predetermined operation or input of information is performed under the power saving mode, the operation condition of the device is returned to the normal mode. In this specification, an operation for switching operation conditions of a device, that is, an operation for switching between the normal mode and the power saving mode of a device, is referred to as “a mode switching operation”, and control associated with switching of the operation modes of a device is referred to as power saving control. In addition, the power saving mode is also referred to as an energy saving mode or a standby mode.
A technology for controlling in a coordinated manner a plurality of devices included in a network system and connected to one another via a network has been known (for example, refer to JP-A-10-49267).
In addition, International Publication No. 01/73558 and JP-A-2000-339116 are examples of related art.
In the case where a plurality of devices connected to one another via a network are used by users, power saving control is performed independently for each of the devices. Accordingly, a device which has not been used by the users for a specific period of time independently moves to a power saving mode even though not desired by the users. Therefore, there is a possibility of increasing user convenience with respect to power saving control in a network system including a plurality of devices connected to one another via a network.
In the case where all the devices connected to one another via a network have moved to a power saving mode at a time, a user who desires to use any one of the devices afterward needs to wait until completion of switching from the power saving mode to a normal mode of the device. In this case also, with respect to power saving control in a network system including a plurality of devices connected to one another via a network, there is a possibility of increasing user convenience.